Commit 15139a3e97 wrongly removed 'vpx' from plugins-good which
is needed to play WebM files on the CC6UL.
The packagegroup-dey-gstreamer also needed to be updated to use
'pulseaudio' from plugins-good which was apparently renamed from 'pulse'.
Signed-off-by: Hector Palacios <hector.palacios@digi.com>
https://jira.digi.com/browse/DEL-6029